<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Log_in</title>
</head>
<body>
    <h1>Log in</h1>
    {% if error %}
    <p><strong>Error: </strong> {{error}}</p>
    {% endif %}

    <form action="" method='POST'>
        <dl>
            <dt>Username:</dt>
            <dd>
                <input type="text" name="username" id="username" 
                    value="{{request.form.username}}" />
            </dd>
            <dt>Password:</dt>
            <dd>
                <input type="password" name="password" id="password">
            </dd>
        </dl>
        <p><input type="submit" value="Login"></p>
    </form>
</body>
</html>